Post-Polio Syndrome (PPS)
For more than 100 years, it has been recognized that late sequelae
of polio occur in some patients many years after the initial illness. The
first description appeared in 1875 in France.
Terminology:
- Late onset PPM progressive muscular atrophy.
- Late progressive PPM muscular atrophy.
- Progressive post-polio atrophy.
- Progressive post-polio muscular atrophy.
- Late effects of polio.
- Post-polio syndrome.
The term syndrome implies a group of symptoms that collectively
characterize a disease or disorder.
Clinical picture:
Neuromuscular symptoms, which include:
- Muscle weakness.
- Fatigue.
- Muscle and joint pain.
- Functional deterioration.
Patients most at risk for PPS:
- Patients who had more severe initial onset.
- Patients who were older when they had initial poliomyelitis.
- Patients who had minor accident, prolonged bed rest or excessive
weight gain.
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Common muscles affected:
- Previously affected muscles which recovered or those which were not
previously affected.
- Symmetrical or asymmetrical affection.
- Unilateral or bilateral affection.
Percentage of PPS:
- Accurately unknown (25 - 40 %).
- It occurs after 30 to 40 years from the initial onset (8 to 50 years).
Etiology:
1. Functional etiologies:
a) Disuse weakness: It causes a decrease in muscle strength and
cardiovascular function. Indirectly, disuse plays a role in loss of
neuromuscular function.
b) Overuse weakness: It leads to functional deterioration. This is
explained by the greater energy consumed by the polio survivors (3 times
the normal). It may be also due to the patient’s desire to appear as near to
normal as possible (greater metabolic demand).
2. Patho-physiological etiologies:
- Reactivation of poliovirus by unknown trigger mechanism.
- Normal aging of the remaining motor neurons.
- Premature aging of the normal motor neurons due to greater metabolic
demands.
- Genetic predisposition of motor neurons to premature degeneration.
- Immune-mediated syndrome.
- Inability of the giant motor units to sustain greater effort (greater
metabolic demand of their sprouts).
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Management:
Differential diagnosis:
As PPS is diagnosed by exclusion, every patient should be
examined by:
* Careful history.
* Laboratory and X-ray examination.
* Physical evaluation.
Criteria:
- Paralytic polio in infancy or childhood.
- Partially-to-fairly complete recovery.
- A period of functional stability for many years.
- Gradual or abrupt onset of one or more new problems (functional
deterioration).
Treatment:
Goals:
- To provide the patient with education and counseling about the causes
of his illness and the problems associated with it (no pain, no gain).
- To prevent exercise-induced muscle weakness.
- To minimize energy expenditure.
- To decrease stressful physical and emotional conditions.
Methods:
Generally, overuse atrophy should be distinguished from disuse
atrophy in polio:
a) With overuse atrophy, slowly progressive non-fatiguing exercises are
recommended (aerobic exercises).
b) With disuse atrophy, general conditioning exercises are preferred.
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It
should
be
noted
that
resistive
muscular
training
is
contraindicated for both affected and non-affected muscles. This is based
on the fact that the non-affected muscles of post-polio patients often work
harder than the muscles of the healthy individuals in order to compensate
for the weakness of the affected muscles and joints. So, the optimal
management of PPS consists of a balance of “not-too-much and not-toolittle exercises”, based on the patient’s subjective reports of fatigue.
Treatment of PPS patients includes:
1. Stretching of shortened muscles.
2. Strengthening of weakened muscles.
3. Gait training.
4. Pacing of activity.
5. Orthotic management.
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